Amstrad 6128 Plus Capacitor Replacement Guide
The Amstrad 6128 Plus has ten aluminium electrolytic capacitors in five values, all with 100-series references on the main board. The values, references and part numbers below are from the 6128 Plus electrical parts list on page 22 of Amstrad's service manual.[1] The board runs from 5 V only. The replacement procedure is the same as on the 464 Plus and is in the Amstrad 464 Plus Capacitor Replacement Guide.
Electrolytic capacitors
[edit | edit source]| Value | Circuit reference | Amstrad part no. |
|---|---|---|
| 470 µF / 10 V | C130, C139 | 270963 |
| 100 µF / 10 V | C135, C136 | 193226 |
| 47 µF / 16 V | C151 | 157629 |
| 10 µF / 16 V | C126, C132, C134 | 157581 |
| 1 µF / 50 V | C137, C138 | 157563 |
The 464 Plus list for the same board design gives C136 as 470 µF / 10 V and has no C139, and adds the five 300-series cassette capacitors.[1] On the 6128 Plus schematic C139 sits on the disc drive's 5 V feed after the choke L104; the same schematic draws C136 as 470 µF with a note giving 100 µF 10 V for one model, and the 6128 Plus parts list gives 100 µF.[2] Check the value printed on each part on your own board before ordering.
Amstrad's board drawing labels the main-board parts without the leading 1 used in the parts list: C126 appears as C26, C139 as C39, and so on.[3]
Other capacitors
[edit | edit source]The parts list gives ceramic capacitors of 100 pF (C127, C131), 330 pF (C124, C125) and 0.1 µF 12 V decoupling (C101, C102, C104, C108, C110, C111–C115, C117, C118, C401), and polyester capacitors of 0.001 µF (C122), 0.01 µF (C103, C120, C123) and 0.047 µF (C121).[1] They are not part of a routine recap. The EME-157 drive is listed as a complete unit (FDD201, part 271611) with no component list.[1]
Safety
[edit | edit source]The computer carries no mains voltage. The MM12 and CM14 monitors do, and hold a high voltage on the CRT; Amstrad's monitor pages call for an isolation transformer and a discharge before the anode cap is removed.[1] See CRT Discharge Procedure.
After the recap
[edit | edit source]Before recapping, measure 5 V at J104 with the computer running; Amstrad's manual also names its RP11 diagnostic ROM cartridge for fault-finding on this range.[4] After it, measure again. Amstrad sets both monitors to 4.80 V under a 2.4 A load and no more than 5.25 V with no load, so about 4.8 V is normal.[1] Then start the machine with its cartridge, run CP/M Plus from the system disc, and read and write a scratch disc.
Related pages
[edit | edit source]- Amstrad 6128 Plus · Amstrad 6128 Plus Maintenance Guide · Amstrad 6128 Plus Troubleshooting Guide
- Amstrad 464 Plus Capacitor Replacement Guide – procedure and the 464 Plus list
- Amstrad CPC 6128 Capacitor Replacement Guide
- Capacitor Failure Symptoms · Recommended Tools
References
[edit | edit source]- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 Amstrad plc, 464 PLUS Home Computer / 6128 PLUS Home Computer / GX4000 Games Console / MM 12 Monochrome Monitor / CM 14 Colour Monitor Service Manual. Described at Amstrad 464 Plus / 6128 Plus / GX4000 Service Manual. 6128 Plus PCB views pp. 16–17; 6128 Plus electrical parts list p. 22; 464 Plus electrical parts list p. 14; MM12 adjustments p. 37; CM14 adjustments p. 44.
- ↑ Amstrad plc, 464 PLUS / 6128 PLUS / GX4000 / MM 12 / CM 14 Service Manual, p. 18 "Gate Array/Output Interface Schematic Diagram" ((C139) 10V470 on the disk drive power feed after (L104); C136 10V470 with the note "C136:M254=10V100"). Described at Amstrad 464 Plus / 6128 Plus / GX4000 Service Manual.
- ↑ Amstrad plc, 464 PLUS / 6128 PLUS / GX4000 / MM 12 / CM 14 Service Manual, p. 16 "Main/Cassette Hold/LED P.C.B. (Top View)" (board MC0122A). Described at Amstrad 464 Plus / 6128 Plus / GX4000 Service Manual.
- ↑ Amstrad plc, 464 PLUS / 6128 PLUS / GX4000 / MM 12 / CM 14 Service Manual, p. 2 "Note to engineers". Described at Amstrad 464 Plus / 6128 Plus / GX4000 Service Manual.